Nuclear Engineering Concepts: Working Outline

Why is CANDU designed the way it is?

 (by W.Garland)

Context Level

'Why' based on social needs and issues

• Comparison to alternate energy forms

Plant Level

'Why' based on the fundamentals that span a number of systems

• clean sheet approach
  • fission
    • fission products
      • kinetic energy -> heat
        • decay heat
          • long term cooling
        • cooling
        • useful work via heat engine
          • heat removal
          • heat rejection
        • process heat
      • radiation inventory
      • risk
        • workers
        • public
    • radiation
      • shielding
      • material damage
    • burnup
      • refueling
    • fuel and moderator design
    • measurement
      • process control
• plant design assessment
  • critique of existing designs
    • simple calculations to evaluate certain effects
    • criteria
      • coolant temperature
      • erosion / corrosion
      • vibration / fretting
      • fluence
      • measurement / control
      • pressure
      • cost
        • algorithms
      • legacy
        • seminal papers
  • engineering limits
    • velocity
    • quality
      • erosion / corrosion
      • swell / shrink
      • CHF
  • design decisions
    • horizontal channels
    • refuelling
    • thermosyphoning
      • placement of heat sinks and sources
    • fuel
    • coolant
    • moderator

Systems Level

'Why' based on system level considerations

• reactor physics
• heat transport system
  • how does it work?
    • flow balance
    • heat duty diagram
    • HTS efficiency vs thermodynamic efficiency
      • need high T, therefore high P
    • heat balance
    • layout
    • pump NPSH
    • flow control
      • on / off pump
      • variable quality
  • optimization
    • D2O holdup
    • feeder layout
      • tube growth accommodation
    • pipe sizing
  • options
    • pros and cons of boiling
    • alternate coolants
    • separate moderator
  • ideal HTS
    • low pressure
    • high T
    • high heat capacity
    • high conductivity
    • good moderator
    • low friction
    • cheap
    • coolant doesn't decompose
    • coolant doesn't become radioactive
    • coolant is non-corrosive
• secondary side
• balance of plant
• chemistry

Component Level

'Why' based on component characteristics and limitations

• valves
• pumps
• instrumentation